Wednesday, September 21, 2011

#Fukushima I Nuke Plant: Reactor 2 Containment Vessel May Have Had a Hole Right After March 11 Earthquake

according to a government researcher at Japan Atomic Energy Agency (JAEA).

Yomiuri Shinbun (9/22/2011):


The simulation done by Yasuteru Shibamoto, researcher at Japan Atomic Energy Agency, shows that the Containment Vessel of Reactor 2 at Fukushima I Nuclear Power Plant may have been damaged, and had a hole about 7.6 centimeters in diameter right after the March 11 earthquake.


It is the first time that the degree of damage on the Containment Vessel is estimated in numbers. It was announced on September 21 at the fall conference of the Atomic Energy Society of Japan in Kitakyushu City.


In simulation, Shibamoto utilized the data TEPCO had announced regarding the operation of the reactor core isolation cooling (RCIC) system and the change in pressure [inside the Containment Vessel]. In 14 hours after the earthquake hit, the water supply to the RCIC was switched from the condenser storage tank that had run dry to the suppression pool at the base of the Containment Vessel.


As the heat wouldn't dissipate, the pressure should have risen to about twice the design pressure (the design pressure is about 5 atmospheric pressures) within 2 days after the quake. However, in the actual data, the rise of the pressure was gradual, and it took more than 3 days to reach 7 atmospheric pressures.

I see. So when the water source was switched from the tank to the suppression pool, the pressure didn't rise because the Containment Vessel already had a hole in it. Then the suppression pool blew up on March 15.

The article doesn't say where the hole might be, or exactly when it may have been created and how.


steve the jew said...

"As the heat wouldn't dissipate, the pressure should have risen to about twice the design pressure (which is about 5 atmospheric pressures) within 2 days after the quake."

very confusing wording. the way it tends to read is that after 2 days the pressure inside was 5 atmospheres.

something like this might be clearer:

As the heat wouldn't dissipate, the pressure should have risen to about twice the design pressure within 2 days after the quake. Since the design pressure is 5 atmopheric pressures a total of 10 atmospheric would be expected.

Anonymous said...

steve, something like this might be clearer:

Rather than "very confusing wording", you should have said 'somewhat confusing wording', and, rather than "the way it tends to read is that after 2 days the pressure inside was 5 atmospheres", you should have said as ex-SKF said, ""it took more than 3 days to reach 7 atmospheric pressures", which based on Shibamoto's simulation is direct indication of a hole/holes in Containment as the design pressure (about 5 atmospheric pressures) should have read 10 atmospheric after 2 days."

Got it?

Anonymous said...


You should find the link I'll include after a little explanation to be enlightening on the topic of Public Relation efforts, past connections to GE, and feeding at the trough(s) of govt. funding. Not to mention to spying upon people and corporations, for decades. Media, broadcasting equipment ...

scroll down to "Gale Directory of Company Histories:
Harris Corporation"

Anonymous said...

Radiation, Inc., indeed

arevamirpal::laprimavera said...

Thank you for your English lessons for the speaker of English as the second language. Much appreciated. I try not to "over-translate" either Japanese or English and say what's decidedly not there in the original, and when I have to I either use the square brackets or comment outside the translation part of the article.

In this case, to write as you suggested would be over-translation. I removed the relative pronoun "which" and replaced with "the design pressure" if that helps.

Atomfritz said...

This is highly interesting.

Please remember that reactor 2 is officially responsible for 99% of all releases up to now, so we need to understand what happened at reactor 2.

The simulation thus indicates that the reactor water circuit could have been broken open directly after the earthquake.
The computed size of the breach suggests that some pipe could have been broken, leaking water/steam into the drywell.
There are a number of pipes with diameter around 3 inches (respective 7.6 cm) attached at the RPV.

So, the first question is:
which tubes possibly could have led to an outcome like this when popping off like apparently happened?

And the second, way more important question:
Can it be justified to continue operating nuclear plants in areas like Japan, when they can easily catastrophically fail in such a manner, without even needing a station black out?

Anonymous said...

And a third question 10:33,
Why do you say Reactor 2 is responsible for 99% of emissions?

Anonymous said...

To poster above: that is one of the estimates put forward by Tepco. Actually I think the offical story is that 90% (not 99%) of the contamination is the result of reactor #2. I'll try to find a link.

Anonymous said...


don't go out of your way, if it even comported with nighttime time-lapse video of steaming events I'd begin to believe it.

Then again, the IR images of building 2 did show complete uniformity of heat signature and its temperature is still high, ..

TEPCO is of course not quantifying honestly explosion debris from the others.

Anonymous said...

See this excellent report which would confirm (it seems to me) that the earthquake caused the LOCA in Unit 1 and now it would seem in Unit 2 as well.

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